Small study. Big health claims. Trade group involvement. It’s a pattern we’ve seen time and again in news releases linking a food to a questionable health benefit.

Long considered a downmarket cooking oil with ho-hum health benefits, cottonseed oil has now been linked to lowering cholesterol, according to a recent news release from the University of Georgia. As the release explains, “researchers suggested a fatty acid unique to cottonseed oil, dihydrosterculic acid, may help prevent the accumulation of triglycerides, a type of fat, in the body.”

Perhaps that’s true. But before we all run out and make cottonseed oil the new extra virgin olive oil, there are key red flags in the research to keep in mind. Namely, the tiny study size (just 15 men), and the length of study time (5 days). And then there’s a detail that lurks at the very end of the release: The study was funded in part by Cotton Incorporated, the trade organization representing U.S. cotton growers.

Small study. Big health claims. Trade group involvement. It’s a pattern we’ve seen time and again in news releases linking a food to a questionable health benefit. It also happens with larger observational studies that can’t establish a cause-and-effect pattern. For example, just yesterday, the California Walnut Commission and the American Heart Association promoted what even they admit are preliminary results related to eating nuts.

‘Readers should always be skeptical’

Fortunately, these kinds of claims have received some news scrutiny, such as this 2016 piece by Eater. But the corporate-backed PR machines that help turn ordinary foods into “superfoods” are still going strong–and both journalists and consumers need to digest these news release headlines with a heaping serving of skepticism.

“Research paid for by food companies generally shows what is known as the ‘funding effect’—the results almost invariably favor the sponsor’s marketing interests,” explained Marion Nestle, PhD, professor emeritus at New York University and author of Unsavory Truth: How Food Companies Skew the Science of What We Eat. “Readers should always be skeptical when an industry-funded study reports a ‘breakthrough’ or suggests that ‘everything you thought about nutrition is wrong.'”

Last week it was Big Cotton. Over the summer it was this news release from Big Cherry touting that “Montmorency tart cherries may help enhance gut health,” by increasing “good bacteria” in people’s digestive systems. The study was short (one week) and small (9 people).

As our reviewers noted, “this study did not show that Montmorency tart cherries may enhance gut health, and this news release did not even explain that there’s no scientific consensus on what defines ‘good’ bacteria, ‘bad’ bacteria, or a ‘healthy’ gut.”

‘Vague…preliminary…too simple’

Just a month before, Big Mango took a turn, claiming a study showed “mangoes helped improve cardiovascular and gut health in women.” Again, short study (27 days) with low enrollment (24 women). There was no control group, so it’s actually impossible to know if any health benefits were due to the mangoes or something else.

“Given the vague nature of the reported findings, the fact that the relevant research paper is not publicly available (at the time of this review) and the preliminary nature of the study, the question becomes: Why issue a news release on this now?” our reviewers pondered.

And if we go back to this spring, the same pattern surfaces in this news release from the National Pecan Shellers Association. Twenty-six participants ate pecans daily for a month, leading to better “metabolic health.”

Our reviewers weren’t pleased. “People are hungry for good advice on how to eat in order to lessen their risk of chronic diseases, including cardiovascular diseases. But this short news release paints a too simple picture based on a month-long study of a few patients,” they noted.

Big Avocado, Big Raspberry, Big Pasta, Big Mango…should we go on?

When we started to search our archives of 600+ news release reviews, we realized the examples above were but a few we’ve got on hand. We’ve also analyzed health claims from these trade groups, among others:

As these reviews indicate, many news releases inflate study findings and minimize limitations. Industry involvement isn’t always made clear, often found in the fine print versus upfront. This doesn’t stun Yoni Freedhoff, MD, medical director of the Bariatric Medical Institute at the University of Ottawa and a HealthNewsReview.org contributor.

“A trade group’s job isn’t to promote or protect public health, but rather to promote and protect the sales of their products,” he said. ” …Journalists who uncritically amplify their views, are doing their readers a great disservice.”